This invention relates generally to bearings and more particularly to journal bearings wherein a cylindrical shaft rotates in a journal sleeve with an oil film supporting and separating the shaft surface from the journal surface to protect the two surfaces against destroying each other.
Normally journal bearings include a cylindrical shaft rotating in an annular bearing sleeve having a circular bore with a diameter that is slightly larger than the diameter of the shaft in order to provide an operating clearance for the bearing. An oil film exists in this clearance to support the shaft and prevent it from engaging the surface of the bearing sleeve. Usually the shaft is not located exactly along the axis of the bearing sleeve but is displaced from such axis slightly so that it rotates about an axis that is eccentric to the bearing sleeve axis. Designers of machinery would like to reduce the clearance between the shaft and the bearing sleeve to a minimum so that the bearing has a high stiffness, i.e. zero play. However, the reduction of the clearance unduly causes the bearing to self-destruct and therefore all bearings of this type need a substantial clearance to operate properly. The play in the bearing determines its stiffness and bearings of the aforementioned type have relatively low stiffness because of having substantial play therein.
U.S. Pat. No. 4,624,584, issued Nov. 25, 1986, describes several variations of journal type bearings which are attempts to design journal bearings having higher stiffness. There prior art designs still have substantial play.
The foregoing describes limitations known to exist in present-day journal bearings. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided in the invention disclosed hereinafter.